Coordinated Regulation of Virulence Genes in C. neoformans

项目摘要。在受感染宿主的恶劣环境中生存，致病 微生物必须能够感知和适应不断变化的环境条件。这 适应需要协调调节多种生长和生存因素。像许多 感染剂，人类真菌病原体新型隐球菌使用保守的 信号分子环腺苷酸（cAMP）调节其对外界应激的反应。中央 cAMP信号转导途径的组分在微生物中高度保守。 然而，该提议的主要假设是上游激活信号和下游激活信号是相互作用的。 cAMP的下游效应物在微生物病原体中功能特化。这 特化允许病原生物体使用cAMP信号传导来控制它们的毒力 潜力 cAMP的增加激活了一系列蛋白质的相互作用，使C。 新人类适应宿主环境的能力具体来说，C.新生儿cAMP通路 调节荚膜和黑色素的诱导，这是发病所需的两种细胞因子。这 调节发生在转录水平。因此，本提案的实验将 确定反式和顺式作用的调节元件，介导cAMP对 转录囊膜相关基因。此外，确定受控制的监管网络 通过cAMP依赖性转录因子将使我们能够探索环境中的广泛问题， 传感、细胞应激和微生物毒力。具体目标1提出生物信息学和 转录谱分析方法，以确定控制C.新生 荚膜基因表达具体目标2概述了选定的转录的详细测试 调节剂，以确定其在胶囊诱导中的作用。具体目标3中的实验将定义 在前两个目的中鉴定的转录因子的直接和间接靶基因。

Project Summary. To survive within the hostile environment of the infected host, pathogenic microorganisms must be able to sense and adapt to changing environmental conditions. This adaptation requires a coordinated regulation of multiple factors for growth and survival. Like many infectious agents, the human fungal pathogen Cryptococcus neoformans uses the conserved signaling molecule cyclic AMP (cAMP) to regulate its response to external stresses. The central components of cAMP signal transduction pathways are highly conserved among microorganisms. However, the main hypothesis of this proposal is that the upstream activating signals and the downstream effectors of cAMP are functionally specialized in microbial pathogens. This specialization allows pathogenic organisms to use cAMP signaling to control their virulence potential. Increased cAMP production activates a series of protein interactions that allows C. neoformans to adapt to the host environment. Specifically, the C. neoformans cAMP pathway regulates the induction of capsule and melanin, two cellular factors required for pathogenesis. This regulation occurs at the level of transcription. Therefore, the experiments of this proposal will identify trans- and cis-acting regulatory elements that mediate the effect of cAMP on the transcription of capsule-associated genes. Moreover, defining the regulatory networks controlled by cAMP-dependent transcription factors will allow us to explore broad issues in environmental sensing, cellular stress, and microbial virulence. Specific Aim 1 proposes bioinformatic and transcriptional profiling approaches to identify transcription factors that control C. neoformans capsule gene expression. Specific Aim 2 outlines detailed testing of selected transcriptional regulators to define their role in capsule induction. Experiments in Specific Aim 3 will define the direct and indirect target genes of the transcription factors identified in the first two Aims.